How can you Categorize computer memory? Discuss in details.
Introduction:As the word implies “memory” means the place where we have to store any thing, this is very essential part of human being just like this memory is also very important for computer system because in computer system we have to store some data or information and for storing these items we need some memory or space.
Types of Memory
1. Internal Processor Memory or built i memory
2. Main Memory
3. Secondary Memory/Storage/Auxiliary Memory
1. Internal Processor memory (or built in memory):
This memory are 3 kinds:
(i) Register (inside the processor)
(ii) Cache (Inside the processor)
(iii) Buffer (outside the processor and known as Butter [RAM]
(i) Register (inside the processor):
A register may hold an instruction, a storage address, or any kind of data (such as a bit sequence or individual characters). Some instructions specify registers as part of the instruction
(ii) Cache (Inside the processor):
Cache memory is a small-sized type of volatile computer memory that provides high-speed data access to a processor and stores frequently used computer programs, applications and data. It is the fastest memory in a computer, and is typically integrated onto the motherboard and directly embedded in the processor or main random access memory (RAM).
(iii) Buffer (outside the processor and known as Butter [RAM]:
Buffer is a temporary holding area for data while it's waiting to be transferred to another location. It is usually located in the RAM
2. Main Memory: (i) RAM :
Random Access Memory is volatile. That means data is retained in RAM as long as the computer is on, but it is lost when the computer is turned off. When the computer is rebooted, the OS and other files are reloaded into RAM, usually from an HDD or SSD.
(a) Static RAM (SRAM):
Static random-access memory (static RAM or SRAM) is a type of semiconductor memory that uses bistable latching circuitry (flip-flop) to store each bit. SRAM exhibits data remanence, but it is still volatile in the conventional sense that data is eventually lost when the memory is not powered.
(b) Dynamic RAM (DRAM):
Dynamic random-access memory (DRAM) is a type of random access semiconductor memory that stores each bit of data in a separate tiny capacitor within an integrated circuit. The capacitor can either be charged or discharged; these two states are taken to represent the two values of a bit, conventionally called 0 and 1.
(ii) ROM:
ROM is "built-in" computer memory containing data that normally can only be read, not written to. ROM contains the programming that allows your computer to be "booted up" or regenerated each time you turn it on. Unlike a computer's random access memory (RAM), the data in ROM is not lost when the computer power is turned off. The ROM is sustained by a small long-life battery in your computer.
(a) PROM:
Short for programmable read-only memory, a memory chip on which data can be written only once. Once a program has been written onto a PROM, it remains there forever.
(b) EPROM :
EPROM : Acronym for erasable programmable read-only memory, and pronounced ee-prom, EPROM is a special type of memory that retains its contents until it is exposed to ultraviolet light.
(c) EEPROM:
EEPROM : Short form of electrically erasable programmable read-only memory. EEPROM is a special type of PROM that can be erased by exposing it to an electrical charge.
3. Secondary Memory:
(i) Hard disc
These are used for storing data/information permanently. CPU directly does not access these memories, instead they are accessed via input-output routines
(ii) Portable Hard disc/Flash drive:
An external hard drive is a portable storage device that can be attached to a computer through a USB or FireWire connection, or wirelessly. External hard drives typically have high storage capacities and are often used to back up computers or serve as a network drive.
(iii) CD:
Compact Disk (CD) is portable disk having data storage capacity between 650-700 MB. It can hold large amount of information such as music, full-motion videos, and text etc. CDs can be either read only or read write type.
(iv) DVD :
Digital Video Disk (DVD) is similar to a CD but has larger storage capacity and enormous clarity. Depending upon the disk type it can store several Gigabytes of data. DVDs are primarily used to store music or movies and can be played back on your television or the computer too. These are not rewritable
Conclusion:
Although computer memory is different and their work is different, they are related to each other while working. If a part is broken, the whole system is stuck. Therefore, the importance of all the memory is equal.x